MATLAB: Reading varying headerlines length, text files

headerMATLABtext files

Hi, I am trying to read specific part of the header lines for these files and once I read lines i want to increment for each block and display them into GUI edit text boxes.
fid= fopen([FilesToRead, MultipleFiles]);
textForGUI = cell(1);
while true
    tLine = fgetl(fid);
    headerCells = strsplit(tLine,' ');
    if length(headerCells) > 1
        if ~isempty(headerCells{2})
            if ~strcmpi(headerCells{2},'!User') && ~strcmpi(headerCells{2},'data')
                textForGUI(end+1) = headerCells(2);
            else
                break
            end
        end
    end
end
textForGUI = textForGUI(2:end);
Block=0;
while true
    tLine = fgetl(fid);
    if ~ischar(tLine) 
       break;
    end
    if ~isempty(strfind(tLine,'data'))  
      Block=Block+1;   
    if true
      % code
    end
       formatSpec = '%f %f %f %f %f';       
       C = textscan(fid,formatSpec,24,'CommentStyle','data','Delimiter','\t');
       %here I got some calculations and plots
      end
  end
Thanks!

Best Answer

I usually find the easiest way to do this sort of thing is to read the whole file in as plain text (assuming it's not too large), and then parsing out the bits I want using strfind and regexp as appropriate. Here's an example:
fid = fopen('~/Downloads/Example-2.txt');
tmp = textscan(fid, '%s', 'delimiter', '\n', 'whitespace', '');
tmp = tmp{1};
fclose(fid);
% Figure out where each header section begins and ends
sidx = find(~cellfun('isempty', regexp(tmp, '^\d*\s*\*\*\*letter')));
eidx = find(~cellfun('isempty', regexp(tmp, '^\d*\s*high')));
% Assume data runs from end of one header to beginning of next
dsidx = eidx + 1;
deidx = [sidx(2:end)-1; length(tmp)];
% Loop over blocks
nblock = length(sidx);
C          = cell(nblock,1);
textForGUI = cell(nblock,1);
for ii = 1:nblock
      % Read the header block and data block
      headerlines = tmp(sidx(ii):eidx(ii));
      datalines = tmp(dsidx(ii):deidx(ii));
      % Throw away the data lines you don't need (!user, data, blank)
      datalines = regexprep(datalines, '^\d*', '');
      isgood = cellfun('isempty', strfind(datalines, '!user')) & ...
               cellfun('isempty', strfind(datalines, 'data')) & ...
               ~cellfun('isempty', strtrim(datalines));
      datalines = sprintf('%s\n', datalines{isgood});
      % Read numbers from cleaned-up data block
      formatSpec = '%f %f %f %f %f';       
      C{ii} = textscan(datalines,formatSpec,24,'CommentStyle','data','Delimiter','\t');
      textForGUI{ii} = headerlines(2:end);
end
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